I wired a Crate GX15 into 3 separate speakers instead of 1, and turned a pair of old computer speakers into an overdriven 2nd channel.
Step 1: Gluing and Compressing the Plywood Speaker Panel
So I cut identically sized pieces, spread a thin layer of wood glue between them, and (as you can see in the pic) clamped the hell out of them! Once dry and trimmed to size, the profile was seamless.
Step 2: Components Used for the Build
2. Crate GX15 amplifier and speaker
3. Speaker from a Champion 600 amp
4. Other 4" speaker
Holes were cut with an electric drill and jigsaw.
Lucky the potentiometers were threaded, so I was able to firmly attach the whole circuit board to the housing.
I don't have any metal bending equipment, so I put the faceplate in my bench vise, then attached my vise grips to the tab hanging out, and bent it 90 degrees - it wasn't a bad way to do it...